Memory problems are widespread but little has been done to exploit information technology to help. People have many procedures designed to compensate for their fallible memory, for example, writing lists, organizing things in files, putting notices on notice boards and setting alarms. Even in a well-organized setting, things might be mislaid or forgotten because they were not seen to be important at the time they were encountered. These failures of memory have a cost, both in the time spent recovering (such as looking for mislaid documents) and in the time spent organizing things in the first place so that problems do not arise.
One current form of memory aid is the electronic personal organizer, which is similar in form to a hand-held calculator. Although such a device is capable of holding large amounts of information, each item must be entered, usually manually, so the user must both input the information and remember to do so.
Various other systems have recently been proposed to help the user recall past events as well as to provide reminders of future intentions. For example, in EP-A-0,495,622 to Lamming et al. there is described an activity-based information retrieval system which automatically captures and records certain aspects of the context in which a recorded event took place. The system relies on a variety of apparatuses for monitoring, recording and time-stamping various key aspects of human activity, from which a readable list of episodes, or `activity diary` can be generated automatically. In one example, the system uses encoded identifiers, each intended to be carried by people working in the environment being monitored. One particularly convenient form of identifier is the "active badge" offered by Olivetti. This identifier takes the form of miniaturized circuitry in a housing able to be pinned or clipped to the clothing of the person to whom the identifier is issued. The circuitry is designed to emit pulse width modulated infra-red (IR) coded signals for a tenth of a second every 12 to 15 seconds. The signals, by their nature, have a range of about six meters, and will not travel through walls, which makes them very useful for keeping track of people moving between rooms in a normal working environment. In each of the rooms or corridors of interest would be positioned one or more sensors responsive to the IR signals. The sensors would be connected to a master station processor, which would have the task of polling the sensors for identification `sightings`; processing the data (which would include decoding the signals to determine which person was within range of a specified sensor at the time of polling), and presenting the processed data in a visual format in the form of a diary. This diary, which correlates quite closely with human recollections of past episodes, can be used simply to stimulate further recall, or to identify an episode and its time of occurrence, or to show a set of episodes from different sets. The time may be used to locate the corresponding items in any other set of time-stamped data, such as a sequence of video frames or an audio record of a meeting.
A related system was disclosed in an article in The Sunday Times of London, U.K., 11 Feb. 1990, entitled "Computers acquire social skills", by Jane Bird. This mentioned the use of identity buttons to enable the computer to know who was where in the building at all times. Associated with the system is a network of microphones and/or video cameras capable of recording conversations. It gave the example of a copier in a room monitored by the computer. Upon the copier's developing a fault, a frustrated would-be user tries to recall what a colleague told him about how to cure the fault. The computer is interrogated to find the last time that the two people concerned were at the copier. Once this particular bit of information has been recovered, it is used to access the time-stamped audio records of what was said in the room containing the copier at that point of time. In this way, the inquirer has the opportunity of hearing again the conversation between him and his colleague.
The aforementioned systems have several practical limitations. These include the need on the part of the user to devote a lot of effort to identifying a particular time and place from the raw data, and the lack of precise episode definition from such data. Also the systems capture just the location of users, and not their activity or other significant episodes. These drawbacks would make the systems of relatively little practical value.
It is an object of the present invention to provide an improved memory aid system which requires minimum input from a user, and yet which is easier to use for retrieving information than to remember or find whatever it is that has been forgotten or mislaid.